NILES, Mich. - Sunday, April 1 marks one year to the day since the fatal carbon monoxide poisoning at the Niles Quality Inn. For the first time ever, we're revealing what led up to that fateful day in the words of the hotel owner and inspector.

That morning in 2017, a pool heater leaked the toxic fumes into the pool area, killing 13-year-old Bryan Douglas Watts and poisoning more than ten others as well.

Since then, the victims have filed a lawsuit alleging negligence against the people they believe are to blame.

Back in December, you heard from the mother of Bryan Douglas Watts about how the tragedy has affected her.

Her attorney, Ven Johnson, has filed an amended complaint with more victims against the hotel owner, the franchisor, the inspector, the seller of the hotel, and the company that originally installed the pool heater.

Attorneys are still in the process of taking depositions, but Johnson has released the depositions of Ms. Watts, the hotel owner, Jay Patel, and the inspector, Mark Modlin, exclusively to ABC 57.

“Their lives, every one of them has been forever changed...We want to hold the people accountable who are all accountable," said the victims' attorney, Ven Johnson.

His team says two of the main people at fault are hotel owner, Jay Patel, and the inspector he hired, Mark Modlin.

“First and foremost about Mr. Patel that he bought the hotel the year before and that from the date that he bought the hotel, literally had no real game plan in terms of investigating and speculating and checking the pool, I’ll call equipment room," said Johnson.

In Patel's deposition, Johnson asks, "Since you didn't know they were there, at no time before April 1 of 2017 did you ever look at the instructions, because you didn't know they were there. Agreed?"

Patel responds, "No, correct."

"Patel admitted he never even looked at the manufacturer’s instructions for the pool heater. Had them shoved in some drawer in the pool area, didn’t even know they were there until after all this happened," said Johnson.

If he had sought out the manual, he would have come across a page saying, "The following maintenance is recommended every six months: make sure that joints have not slipped partially or completely apart. Check pipes and fittings for cracks or breaks."

Mr. Johnson believes the rusted vent proves Patel did not do that.

If Mr. Patel had followed the six-month guideline, he would have checked the venting system at least once since he bought the hotel in June 2016.

His deposition also reveals that investigators found a hole in the wall leading to the outside plugged with something like a garbage bag.

This hole should have been used as an air outake and/or intake to cycle out the carbon monoxide, according to the manual.

Patel first faults the seller, called AJ in his deposition for not telling him he was leaving a manual in the equipment room, but he mainly blames the inspector he hired for $1400, Mark Modlin with Amerispec, for not alerting him to safety concerns.

Johnson followed up by asking him, "You believe his failure to do his job, meaning Modlin...is part of the explanation of what happened to these poor kids that day. Agreed?"

Patel responds, "Yes."

When Johnson relayed Patel's response to Modlin, the inspector said, "The inspections are not a safety inspection. They are an inspection of the - to see if the equipment is there, but not really for a safety inspection."

"Mr. Modlin said I did nothing wrong. I’m not supposed to investigate. That’s the owner’s responsibility to do this, not mine," said Johnson.

Johnson responded with, "So what you recall doing as part of your inspection is you looked at what I'm going to call the front of the unit, correct?"

Modlin says, "The portion of the unit that was visible from the doorway."

Johnson says Modlin believed taking a picture from across the room sufficed as "inspecting".

Modlin says he's inspected 2,000 furnaces but never a pool heater.

It's unclear exactly how similar they are in mechanics.

“It’s really no different than a home furnace or a furnace for a business...You got to not just take a picture from over here and say yes this works, you got to go around it, you got to look take pictures, and If you see rust, wear and tear, you write in your report," said Johnson.

Modlin says going behind the unit is not part of doing his "good, safe, reasonable job" and that "any reasonable building inspector" would agree with him.

Even with a defective pool heater, a carbon monoxide detector could have warned the pool-goers about the leak.

Mr. Modlin says he was not asked to do any carbon monoxide testing and so was not looking for detectors.

However, he did reveal he has a carbon monoxide detector installed in his own home.

"He never told Mr. Patel about that correct. Mr. Modlin admitted that he used one in his home and had been using it for years because of the safety-related issues, and he uses it in an area at or around of guess what a heater," said Johnson.

Working through who should have said or done what, when, will come with a jury trial.

"We have to prove under Michigan law that it’s more likely than not, so 51% or more that the defendant was negligent, that that negligence led to damages, injuries, and death," said Johnson.

All they can legally ask for is money, but Johnson's team would describe their end goal a little differently.

“The short version to a long story is justice, for Bryan’s family and for each of the victims," said Johnson.

ABC 57 reached out to both Mr. Patel and Mr. Modlin's attorneys.

Mr. Patel's attorney said they don't comment on ongoing investigations, and we are still waiting to hear back from Mr. Modlin's attorney.

Johnson expects the judge to set a jury trial in late fall or early winter.